Today, due to developed wireless technologies, diverse RFID tag reading systems ranging from a prepayment bust card to a parking lot pass and a laboratory pass are used. The RFID tag reading system includes a tag and a reader. The RFID tag reading system operates in the method that if the reader requests tag data transmission to the tag, the tag transmits tag data to the reader in the form of a radio frequency. The reader can be formed in terminals such as a cell phone, a PDA, and a laptop computer. The tag can be implemented in the form of a card which a user can carry such as a pass, and a bus card, or can be implemented in the form of a sticker which is attached to a product to transmit product information.
Meanwhile, according to the method of driving an IC embedded in the tag, there are two types of RFID systems. An active tag supplies power from a battery embedded in the tag, and a passive tag generates an induced current using a magnetic wave transmitted from the RFID reader. Passive tags in the form of a slim and light-weight card are generally used. As the passive tag does not need a battery, it can be miniaturized and low-priced. Accordingly, tags attached to a general product is implemented with passive tags.